Interference canceling matched filters (ICMF) have been investigated to meet requirements for a Downlink Advanced Receiver Performance (DARP) that is standardized by the third generation mobile communications system and the Third Generation Partnership Project (3GPP). Some of these proposals are set forth in the following articles and documents:                1. Slock et al., An Interference Cancelling Multichannel Matched Filter, Globecom November 1996;        2. Trigui et al., Cochannel Interference Cancellation Within The Current GSM Standard, IEEE IC on Universal Personal Communications, 1996;        3. Griffiths et al., An Alternative Approach to Linearly Constrained Adaptive Beamforming, IEEE Trans. AP-30, No. 1, 1982;        4. Pukkila et al., Cochannel Interference Suppression for Constant Modulus Signal, IEEE ICC-2004; and        5. Liang et al., A Two-Stage Hybrid Approach for CCI/ISI Reduction with Space-Time Processing, IEEE Communication Letter Vol. 1, No. 6, November 1997.        
Current Global System for Mobile communications (GSM) cellular systems have to address the co-channel interference (CCI) on the mobile station (MS) side, as well as address the DARP requirements. Some single channel structures and pre-filters have been used to aid in canceling the interference and provide some channel impulse response (CIR) estimation. Moreover, some systems have used maximization of the signal-to-interference to design jointly a single channel space-time filter and the CIR estimation for a single channel. Other systems have used a constrained minimization of the mean-square error to design a single channel space filter. Other systems have used a single channel space filter that is designed by a rank-one approximation of the ML channel estimation. The target applications for these systems have been a base station where a physical antenna array including a plurality of antennas is available.
An ICMF performs “blind” interference cancellation (BIC), as it does not need the knowledge of the channel response of the interferers. Yet, the channel response of the wanted or desired signal still has to be known or be estimated. Further details of the ICMF may be found in an article by Slock et al. entitled “An Interference Canceling Multichannel Matched Filter,” IEEE, pgs. 214-218, November 1996. Moreover, the potential application of ICMFs to Global System for Mobile Communication (GSM) Single Antenna Interference Cancellation (SAIC) is discussed in and article to Slock et al. entitled “Cochannel Interference Cancellation Within the Current GSM Standard,” IEEE International Conference on Universal Personal Communications, 1996.
Despite the advancements in ICMF systems, channel estimation may still be problematic, and thus the DARP requirements difficult to achieve. Accordingly, further advancements in the use of ICMFs in cellular telephone applications, particularly for DARP-compliant devices, are desirable.